Door latch



Aug. 18, 1953 KANELL 2,649,324

DOOR LATCH Filed Jan. 23, 1950 2 Sheets-Sheet 1 IIIIIIIA I g xww 28 I /00095 ZANELL,

0x INVENTOR.

Aug. 18, 1953 T. KANELL 2,649,324

DOOR LATCH Filed Jan. 23, 1950 2 Sheet 'Sheet 2 21/500025 KANELL,

INVENIOR.

BY y

flrraelvsy.

Patented Aug. 18, 1953 DOOR LATCH Theodore Kanell, Los Angeles, Calif., assignor, by mesne assignments, to Alexandria Kompaniez,

Los Angeles, Calif.

Application January 23, 1950, Serial No. 140,080

5 Claims. (01. 292-191) This invention relates to door latches that are urged resiliently to latching position.

Spring latches of this character are usually arranged with a sloping surface that cooperates with the striker plate in a door jamb to urge the latch inwardly as the door is being closed. Upon continued closing movement, the latch leaves the striker plate and the spring urges the latch into a recess defined by the plate.

Often the spring latch serves, as well, as a locking means, b preventing operation of the latch retractor mechanism. However, even when so locked, it is still possible to unlatch the door by inserting an instrument (such as a screw driver blade, or other thin tool) between the plate on the door jamb and the sloping surface. In this way, the latch can be urged inwardly against the spring and released from the striker plate.

Various devices have been provided for supplementarily looking the latch against withdrawal from the plate when the door is closed. Such devices are complicated and expensive, and can often be rendered ineffective, as by a simple sawing operation.

It is one of the objects of this invention to provide a supplemental locking device for preventing unauthorized withdrawal of the latch that is simple and inexpensive, and that can be designed so as to form a part of a complete door lock.

It is another object of this invention to provide a door latch in which there is embodied a restraint cooperating directly with the latch plate, and yet which automatically releases the latch when the knob is turned.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawings acdoor and the latch shown in Fig. 1;

Fig. 3 is a View similar to Fig. 2, but illustrating the latch in retracted or releasing position Fig. 4 is a horizontal section, taken along a plane corresponding to the line 4-4 of Fig. 2;

Fig. 5 is a vertical section, taken along a plane corresponding to line 5-5 of Fig. 4;

Fig. 6 is a fragmentary view similar to Fig. 4, but illustrating the supplemental lock in releasing position;

Fig. 7 is a fragmentary end view as seen from the left-hand side of Fig. 5;

Fi 8 is a fragmentary end view as seen from the right-hand side of Fig. 5; and

Fig. 9 is an exploded view illustrating the main parts of the latch mechanism.

In Figs. 1 and 2, the vertical edge 3 of a door I is shown in closed position with respect to a door frame 2. This edge 3 is shown as slightly sloping to conform with the sloping striker plate 4 mounted on the frame 2. This striker plate 4 has a curved portion 5 cooperating with the curved or sloping surface 6 of the latch bolt body 1. The latch bolt body I is thereby urged inwardly as the door I is closed. Thereafter, the latch body 7 is resiliently urged into an aperture 8 of the striker plate 4 and into a recess 9 formed in the frame 2.

The latch body 1 projects through a plate it disposed in a recess in the door I. This recess communicates with a horizontal cylindrical bore !2 in the door l for the accommodation of the latch casing 13, which slidably supports the latch body 7.

The door lock structure I4 is shown in Figs. 1, 2, and 3. This door lock structure is similar to that described and claimed in a co-pending application filed in the name of Theodore Kanell under Serial Number 134,963, filed on December 24, 1949, and entitled Door Look. The door knobs l5 and it are so arranged that, by turning the knobs, the mechanism for retracting the latch body I is operated.

' The housing is for the lock structure M is accommodated in a cylindrical bore I! passing through the door I and communicating with the horizontal bore l2. The housing I8 is provided with a slot [9 adapted to engage the slots 20 on diametrically opposite sides of the casing l3 (see Figs. 4, 5, 7, and 9). In this way, the latch structure is connected to the lock mechanism.

Retraction of the latch body 1 is accomplished by the aid of a T-head 2| formed on the end of a pull rod 22 extending into the casing l3. This T-head is engageable by a latch grip member 23 operated to retract the body 1 upon turning 3 of either knob l5 or I6, all as described in said prior application.

The casing [3 within which the latch body 1 is slidable is provided with a flared end 24 for the accommodation of the flange 25 attached to the plate [0; thus this plate Ill is afiiXed to the casing. The inner end of the casing l3 has the arcuate segments '26 within which the slots 23 are formed, as well as a plurality of tabs 21. In assembling the casing [3, the tabs 21 are turned inwardly to hold an end washer 28 in place at the right-hand end of the casing 13. As shown most clearly in Fig. 9, this end washer 28 has radial projections 29 entering into the corresponding slots in the casing 1:3, and I8:- straining the washer against removal. The washer 23 is also provided with a rectangular opening to serve as a guide for the rectangular pull rod 22.

The latch body I is urged toward the left, as viewed in Figs. 4 and 5, as by a compression spring 3|. This compression spring extends around the pull rod .22 and ,is enclosed within the casing l3 .and body 1. Its right-hand end abuts the washer 213. and its left-hand end abuts the ends of inwardly projecting fingers 32 stamped integrally out of the latch body 1.

The latch body 1 carries a detent 33 adapted to engage the inner edge of the latch plate aperture 8. A narrow tool, inserted between the sloping edge 3 and thedoor irame 2, might .be applied to the sloping ,suriace :5 by an unauthorized person inan effort to release the latch body :1. The detent '33 prevents this efifort from becoming successful. Accordingly, if the door lock mechanism Ma's :in locked position, it is impossible to open the .door without operation of the appropriate :unlocking ,means.

The :detent 33 m'ayleonveniently be in the form of a hook. This jhook projects throughanarrow slot 3 (see particularly Figs. 5 and 6) in the end of body I. Elhe detent 33 is-carzriedat the extremity of :31! arm 5 that is pivoted within the body I on -.a pin 35. This pin extends transversely across the hollow body 7 and may be attached to theinner wallof zthiS hollow body, as

by soldering, or the like. The body may have a slot 5| (Fig. 14;). .at :itsflef-t-hand end to provide clearance ."for the arm .35.

A spring :member 1321 has a yoke 38 which engages underneath the arm =35. The spring 3! is provided with loops ,39 passing around the pivot pin 36. The free ends 40 of the spring 38 -engage the inner gSllIfElJ CB of the body ,1. The :spring 3l thus-urgeszthe :detent to the active positionof Fig. 4.

by the (so-action ;of ithejstopzsurface M .of slot 3 and a -.corrcsponding stepped surface 1 formed-on thesdetent 3,3. "'Ihesesurfaces-are in engaged p os'ition 'zl'll .Fig. 5.6. .As shown most :clearly in IFigs.- .4 iande lwardly-iextendingypon o .i-thedete aesjhasas o 15 n which fits the inner curveiofathesloping walls.

The vpu-ll rod "2-2 has a -bif,u1?cated portion #6 straddling :a lever arm 41 joined to the -.detent arm 35. .(A asloll-ramd pin --;conne.ction is iprmed @between the: 8116315 5 andifthe .arm A?! as by the; aid :of 4%;9111148 Thispimmaymave its ends-slightly body for movement ,transv,er,se. tossaid. body,v

4 upset. Inward movement of the pull rod 22 is limited by a cross pin 49 that passes through the pull rod and is stopped against the righthand wall of washer 28.

When the pull rod 22 is pulled toward the right, as viewed in Fig. 4, by the aid of a latch grip 23, the detent 33 is rotated downwardly to the position of Fig. 6. In this position the detent is out of the way of the edge of the aperture 8 (Fig. 1). Further movement of the pull rod 22 shifts the entire latch body 1 to the right and, ultimately, to the unlatched position of Fig. 3.

In order to permit the detent 33 to pass the plate Ill, this plate I 0 may be provided with a slot 50 communicating with the main guiding aperture 52 (Figs. 18 and 9).

In the latched position of Fig. 4, a thrust exerted on the wall 6 is ineffective to move the latch body 7 to open position. However, a pull on the pull rod 22 first disengages the detent 33 and then serves, upon conducted movement, to retract the latch body 1.

The inventor claims:

1. In a retractable door latch structure: a longitudinally movable hollow latch body; means forming a guide for the movement of said body; a detent pivotally mounted in the body on an axis transverse to the longitudinal movement of the body; said detent having a retractable opera.- tive portion extending through a slot in the body; resilient means for urging the detent to operating position; said detent having a surface adapted upon retraction of the detent to engage the latch body for limiting angular motion of the detent with respect to the latch body; and means movable longitudinally of said body for applying a retracting force thereto, said means being attached to said detent at a place such that said movable means upon movement in a retracting direction overcomes said resilient means and moves said detent surface into .engagement with said latch body to efiect a connection between said movable means and said latch body.

2. In a retractable door latch structure adapted to cooperate with a latch plate having an edge forming an aperture for the reception of the latch: a hollow longitudinally movable latch body; a detent; means mounting said .i etent within said body for movement tran verse to said body, said detent being movable to one position in which at least a portion ofsaid aperture edge is in the path thereof for relative movement therebetween in a direction corresponding to longitudinal movement of said latch body, said detent being movable to a retracted position in which said aperture edge is out .of the .path thereof for relative movement therebetween in a direction corresponding to longitudinal move ment of said latch body; means urging said ,detent to said one position; means urging said latch body into latching relationship with Said aperture; and means for longitudinally retractmg said body. comprising a lost motion-connection in which said detent forms a part, the lost ,motion corresponding to movement .of said edetent to transverse retracted position.

3. In a retractable door latch-structureadap'ted to cooperate with a latch .platehaving an; edge forming an aperture ,for the reception voi? -;the -latch: .a cylindrical casing; a hollow latch .bpdy u d f r lon tudinal movement .in,.the, ca sing;

a detent; means mounting said detent withinssaid detent being movabletoone position ginwhich at least a portion of said aperture edge is in the path thereof for relative movement therebetween in a direction corresponding to longitudinal movement of said latch body, said detent being movable to a retracted position in which said aperture edge is out of the path thereof for relative movement therebetween in a direction corresponding to longitudinal movement of said latch body; means urging said detent to said one position; a compression spring engaging the casing and the latch bolt for urging said latch bolt into latching relationship with said aperture; and means for longitudinally retracting said body, comprising a lost motion connection in which said detent forms a part, the lost motion corresponding to movement of said detent to transverse retracted position.

4. In a retractable door latch structure adapted to cooperate with a latch plate having an edge forming an aperture for the reception of the latch: a casing; a hollow latch body guided for longitudinal movement in the casing, said latch body having a latch end with a sloping cam surface and a flat surface forming the point of the latch, said flat surface extending in a plane substantially parallel to the direction of guided longitudinal movement of said latch body; said latch body having a slot intersecting said surfaces; a detent; means pivotally mounting said detent in said body about an axis substantially normal to the direction of longitudinal movement of said latch body as Well as substantially parallel to said plane of said fiat surface; said detent being angularly movable to one position in which said detent extends beyond said flat surface in an amount such that said aperture edge is in the path thereof for relative movement therebetween in a direction corresponding to longitudinal movement of said latch body, said detent being movable to a retracted position in which said aperture edge is out of the path thereof for relative movement therebetween in a direction corresponding to longitudinal movement of said latch body; the end of said slot limiting retracted movement of said detent; and a pull rod pivotally connected to said detent and movable in a direction corresponding substantially to the direction of longitudinal movement of said body; movement of said pull rod in a direction corresponding to longitudinal retraction of said latch body moving said detent to said retracted position and into engagement with said slot and for coupling said latch body to said detent for longitudinal retraction of said latch body only after movement of said detent to retracted position and upon continued movement of said pull rod. 5. In a retractable door latch structure adapted to cooperate with a latch plate having an edge forming an aperture for the reception of the latch: a substantially cylindrical casing; a latch body having a latch end extending beyond one end of said casing, and guided for movement by said casing; a detent; means pivotally mounting said detent in said body about an axis substantially normal to the direction of movement of said latch body; said detent being angularly movable to one position in which said detent extends transversely beyond said latch end in an amount such that said aperture edge is in the path thereof for relative movement therebetween in a direction corresponding to the direction of movement of said latch body, said detent being movable to a retracted position in which said aperture edge is out of the path of movement thereof for relative movement therebetween in said corresponding direction; means urging said detent to said one position; a pull rod in said casing and said body and pivotally connected at one end to said detent; a plate carried near the other end of said casing and guiding said pull rod for movement in a direction corresponding to the direction of movement of said latch body; movement of said pull rod in a direction corresponding to retracted movement of said latch body moving said detent to said retracted position; means connecting said detent to said latch body only when said detent is retracted for retracting said latch body upon continued movement of said pull rod in a direction corresponding to retracted movement of said latch body; and a compression spring surrounding said pull rod, and engaging said plate and said latch body for urging said latch body toward latching position.

THEODORE KANELL.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date 699,301 Fogel- May 6, 1902 1,484,500 Hope, Jr. Feb. 19, 1924 1,861,139 Samburg May 31, 1932 

